linux-kernel - RE: [PATCH 1/2] rtc: da9063: set range

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Date:   Tue, 2 Apr 2019 09:37:03 +0000
From:   Steve Twiss <stwiss.opensource@...semi.com>
To:     Alexandre Belloni <alexandre.belloni@...tlin.com>,
        Wolfram Sang <wsa@...-dreams.de>
CC:     Geert Uytterhoeven <geert@...ux-m68k.org>,
        "linux-rtc@...r.kernel.org" <linux-rtc@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Wolfram Sang <wsa+renesas@...g-engineering.com>,
        Support Opensource <Support.Opensource@...semi.com>,
        Linux-Renesas <linux-renesas-soc@...r.kernel.org>
Subject: RE: [PATCH 1/2] rtc: da9063: set range

Hi,

02 April 2019 09:53 Alexandre Belloni, wrote:
> Subject: Re: [PATCH 1/2] rtc: da9063: set range
> On 01/04/2019 21:34:25+0200, Wolfram Sang wrote:
> >
> > Thanks for your assistance! What I did just now was to make use of the
> > 'uie_unsupported' flag. This is the outcome:

[...]

> > I wonder why the_set_minute tests pass, but the other ones fail.
> > [...]
> > I also wonder why all this works fine for Steve.
> >
> 
> I had a look at the driver and I guess you have a 9063AD while Steve
> uses another model.

That would be my immediate guess also.

https://elixir.bootlin.com/linux/v5.1-rc3/source/include/linux/mfd/da9063/core.h#L39

Reading the PMIC register 0x182 and examining the 4 highest bits of that
value will provide the variant code for the DA9063.

> That explains why you need the uie_unsupported flag. The 9063AD can only
> do alarms on a minute boundary.

For AD, alarms only happen to the minute boundary (i.e. alarms to 0 seconds only)
https://elixir.bootlin.com/linux/v5.1-rc3/source/drivers/rtc/rtc-da9063.c#L84

Whereas, BB and greater can alarm to any of the second values 0-59
https://elixir.bootlin.com/linux/v5.1-rc3/source/drivers/rtc/rtc-da9063.c#L113
 
I can confirm that I was only running my previous regression tests with a
BB and CA compliant silicon version. I didn't even think to mention what variant
I was testing with.

[...]

> I suggest the following patch:
> 
> ===
> 
> From 37b2ab7d537e76e42bde64cf4b57701b0ed8e8cd Mon Sep 17 00:00:00 2001
> From: Alexandre Belloni <alexandre.belloni@...tlin.com>
> Date: Tue, 2 Apr 2019 10:06:46 +0200
> Subject: [PATCH] rtc: da9063: set uie_unsupported when relevant
> 
> The DA9063AD doesn't support alarms on any seconds and its granularity is
> the minute. Set uie_unsupported in that case.
> 
> Reported-by: Wolfram Sang <wsa@...-dreams.de>
> Reported-by: Geert Uytterhoeven <geert@...ux-m68k.org>
> Signed-off-by: Alexandre Belloni <alexandre.belloni@...tlin.com>
> ---
>  drivers/rtc/rtc-da9063.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/rtc/rtc-da9063.c b/drivers/rtc/rtc-da9063.c
> index 1b792bcea3c7..53e690b0f3a2 100644
> --- a/drivers/rtc/rtc-da9063.c
> +++ b/drivers/rtc/rtc-da9063.c
> @@ -475,6 +475,9 @@ static int da9063_rtc_probe(struct platform_device
> *pdev)
>  	da9063_data_to_tm(data, &rtc->alarm_time, rtc);
>  	rtc->rtc_sync = false;
> 
> +	if (config->rtc_data_start != RTC_SEC)
> +		rtc->rtc_dev->uie_unsupported = 1;
> +
>  	irq_alarm = platform_get_irq_byname(pdev, "ALARM");
>  	ret = devm_request_threaded_irq(&pdev->dev, irq_alarm, NULL,
>  					da9063_alarm_event,

Thanks Alexandre,

Acked-by: Steve Twiss <stwiss.opensource@...semi.com>

Apologies, I am unable to test this on DA9063 AD silicon since I no longer have
that variant.

Regards,
Steve